Air operated control for machines



Oct. 2l, .1947.

W. C. EWALDSON.

AIR OPERATED CONTROLS FOR MACHINES 5 sheets-sheet 1 Filed Deo. 6, 1944 lll lllllll/IllllllllllL ...1

/Nl/EN TOR WC. EWALDSON A T TORNEV Oct. 21,I 1947. w, C, EWALDSQN AIR OPERATED CONTROLSy FOR MACHINES Filed Dec. 6, 1944 5 Sheets-Sheet 2 /NVE/vrof? WG. EWALDSON Arr /P/vsy Oct- 21, 1947 w. c. EwALDsoN AIR OPERATED CONTROLS FOR, MACHINES Filed Dec. e, 1944 3 Sheets-Sheet 3 A TORNEY Patented Oct. 21, 194.7a

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AIR, OPERATED CONTROL FOR MACHINES Waldemar C. Ewaldson, Millington, N. J., assigner to Western Electric Company, Incorporated, a corporation of New York Application December 6, 1944, Serial No. 566,919

8 Claims. l

This invention relates to air operated controls for machines, and more particularly to air operated controls for punch presses and guards therefor.

Punch presses are frequently used for what are known as rst and second operations, th'e first operation including the blanking of parts from a supply of material, while the second operation includes additional forming or perforating of the blanked parts. a guard is seldom used, particularly when a strip of material is fed automatically to the press, an

During the iirst operation.

operation which does not necessitate the positioning of the operators hands close to the working area of the press. Second operations, however, make it necessary for one or both of the operators hands to move into the working area of the press to position the blanked parts or articles for additional work thereon, and ofttimes to remove the articles from the press.

An object of the invention is to provide a control for a material working machine and a guard therefor which may be operated with a minimum of effort and which is accurate in the actuation of the guard to cover the working area of the machine prior to the operation of the machine.

With this and other objects in view, the invention comprises a control for a material working machine including a tool mounted for movement through an operating cycle into and out of a working position by a power means, a guard movable to shield the working position, a iiuid control unit operable to render the power means eiective, a normally closed valve in a fluid line with the unit to control the unit, an arm actuable to move the guard into the shielding location and mechanism movable by the arm to open the valve to the unit as the guard reaches approximately the shielding location.

Other objects and advantages will be apparent from the following detailed description when considered in conjunction with the accompanying drawings, wherein Fig. 1 is a side elevational view of a material working machine and guard'therefor illustrating the control mechanism; Y

Fig. 2 is a front elevational kview of the structure shown in Fig. 1;

Fig. 3 is an enlarged fragmentary side elevational view of a portion of the control mechanism, and d Fig. 4 is a fragmentary side elevational view of the structure shown in Fig. 3.

Referring now to the drawings, it will be noted that the material working machine selected to illustrate the invention is a punch press indicated generally at I il and including the conventional driving means (not shown) for rotating its drive shaft upon which a flywheel I I is mounted. The conventional clutch mechanism is indicated at I2 and is of the one revolution type, normally in its inoperative position. The clutch I2 is operated through the downward movement of a pull rod I4 operatively connected at its upper end in a suitable manner (not shown) to the operating portions of the clutch, its lower end being connected at I5 to an element I6. Theelement I6 is normally urged upwardly through the force of a spring I'I to normally cause the clutch I2 to be in its inoperative position, The lower end of the element I6 is adjustably secured to a, piston rod i8 of an air cylinder unit I9, the latter being Divotally supported at 20 by a bracket 2I, the latter being mounted upon a base 22 of the press.

It is not believed necessary to describe the inner workings of the press, it being understood that operation of the one revolution clutch I 2 will connect the driving means, including the flywheel I I, with a tool support 25 to move the latter, with a selected tool 216 mounted therein, through a complete cycle of operation from its upper position, through the material working portion of its cycle and back to its normal or upper position. A die 2i, carried by a die block 28, is positioned beneath the tool 26 to cooperate therewith when a material or article 29 is fed to the die. The area, Where work is performed upon the material or article through the aid of the tool or punch 26 and the die 2l, may be called the working Vposition of the machine. It is this position that is to be guarded to assure the removal of the cperators hand prior to the beginning of the operating cycle of the machine.

The guard is of the type shown in Patent Number 1,043,876 to F. C. Spencer of November 12, 1912. In other words, the guard 30 is pivotally supported at 3l upon a bracket 32. The bracket 32 is in the form of a hinge with a pivotal jointy 33 and includes a portion 34 fixed to the head '35 of the machine, the other portion conditioned to be fixed, through the aid of screws 36 or other suitable means, to the head 3'5 to hold the guard in position to guard the working area of the machine and to also condition the guard for movement awayv from the working area to condition the machine for the conventional first operation work, if so desired.

The pivotal support or spindle 3| for the guard, has a pinion 31 fixed thereto and to the guard so f that they will all move in unison about the axis of the spindle. A rack 38, carried by the lever 39, interengages the pinion 31 and serves to rotate the pinion to move the guard into and out of its shielding position when the lever 3B is rotated about its pivot 4B. The pivot 40 is supported at a fixed position on the bracket 32. The end of the lever 39, opposite that of the rack 38, is forked as at 42 to straddle a pin-like portion '43 of a lever arm 44. This connection between the lever 39 and the lever arm 44 assures operation of the guard when the latter is in its operating position and conditions the guard so that it may be rearedly moved into its inoperative position when the bracket 32 is conditioned to swing the guard to one side of the machine.

The lever arm 44 is pivotally supported at 45 and extends rearedly to a position where its apertured end 46 receives an element 41. The element 41 is in the form of a bolt carried by an arm 48 of a bell crank lever 49, the lower threaded portion of the element 41 carrying threaded members or nuts 50 which are adjustable on the element to vary the interval of time in which a valve 5I is actuated after the guard 30 has moved toward its shielding position. The valve 5I is of the normally closed three-way type including a plunger 52 engaged by a cam lever 53, the latter being engaged by the other arm 54 of the bell crank lever 49. Through the aid of a yoke 54 pivotally connected to the lever arm 44 adjacent its rearmost end, a piston rod 55 of an air cylinder '55 is operatively connected to the lever arm.

` The force of a spring 51 normally urges the piston rod 55 upwardly and constitutes the means to return the guard 30 to its normal position, as shown in Figs. l and 2.

A main airline Eil supplies` air under pressure for the control system. The air in this supply line passes through a shut-off valve 6I and a lter 52 to a point `(i3 where the supply line meets air lines 54 and 65. A pressure regulator valve 66 is disposed in the air line 64 for use in regulating the pressure of the air used in the control system, A flexible air hose 61, coupled with the air line 65, extends to a foot Valve 68, the latter being normally closed three-way type operated into open position through the actuation of a treadle 63. An air line 10 leading from the valve 68 to the top of the air cylinder 5E includes a flexible hose or air line 1I and a speed control unit 12. The speed control unit is variable through the adjustment of a threaded element 13 to vary the speed of travel of the fluid and thus vary the speed of movement of the guard into its shielding position.

Returning now to the air line V65, it will be noted that this air line extends from one side of the machine, over the top thereof and down the other side of the machine vto the valve 5I. An air line 14 leads from the valve 5I to the air cylinder I9. It should be understood that both air cylinderslg and 55V are provided with suitable exhaust ports, in their lower portions, so that their inner structures or pistons may be moved downwardly by the admission of air under pressure into the upper portions of the cylinders.

t should also be understood-that the pistons may be returned t-o their upper positions by their respective springs I1 and 51, through the provision of normally open exhausts in the valves 5I and 68 for the fluid lines 14 and 18 respectively.

Considering now the operation of the machine and the air operated control therefor, let it be assumed that the article 29 has been placed upon the die 21 to condition the machine for operation thereon. The operator may then actuate the valve 68 by applying downward pressure upon the treadle 69 to open the valve for the passage of air under pressure to the air cylinder 56 to cause downward movement of the piston rod 55 and clockwise rotation of the lever arm 44. This movement imparted to the lever arm 44 will cause counterclockwise rotation of the lever 39 (Fig. 2) causing the rack 38 to rotate the pinion 31 and with it the guard 38, from the normal position shown, to a position shielding the working area of the machine. If the operators hand should be disposed across the path of the guard, either one of two things will happen; one, the movement of the operators hand free of the working area, or two, the stopping of the guard prior to the actuation of the valve 5I.

Just before the guard 30 reaches its lowermost position, through the actuation of the lever arm 44, the portion 46 of the latter will move into engagement'with the threaded members 50, causing downward movement of the element 41, rocking the bell crank lever 48 about its pivot and opening of the valve 5I through movement of the cam lever 53 and the plunger '52. At this time, the exhaust lof the valve is closed and air under pressure is admitted to the air line 14 and through it, to the air cylinder I9, to cause downward movement of the member I6 and the ypull rod I4, to release the clutch I2 and thus start one operating cycle `of the machine, During this operating cycle, the tool holder 25 with the tool 25, is moved downwardly to cooperate with the die 21 in performing work upon the article.

After the operating cycle has been completed, the guard will be returned to its normal position by the spring 51, it being assumed that the operator will release 'the pressure lon the treadle 69 shortly after its actuation. The control mechanism resets itself through the constant forces in the springs I1 and 51. Through the variations in the positions of the threaded members 5I) upon the element 41, the time interval for the actuation of the valve '5I during the downward swinging movement of the 'guard may be Varied.

It will be observed that to lcondition the machine for what is commonly known `ras rst operation work, wherein the guard is not needed, the guard maybe moved into an inoperative position without alecting the control mechanism. With the guard in its inoperative position, brought about through the removal "of the machine screws 36 and the swinging of the guard about the hinged portion of the bracket 32, the lever ar'rn 44 will continue to cause vactuation of the bell crank lever v49 to open the valve 5I after operation of the foot valve 58 to admit air to the air cylinder 56. Furthermore, during the time when the guard is in its inoperative position, there remains no mechanism which would obstruct the vision of the operator from view-ing the performance of the machine during the vblanking of articles from material. All that remains of the guard actuating mechanism which projects forwardly of the machine, is the lever arm 44 and 'this is positioned above the working area o'f the machine.

Although specific 'improvements of the invention have been shown and described, it will be understood that they are butillustrative `and-that various modifications may be 'made therein without departing from the scope and spirit of this invention as :den'ed by the appended claims.

What is claimed is:

l. A control mechanism for a machine having a material working -tool I''l'ourited 'for lmovement through an operating cycle into and out of a. Working position, clutch controlled power means to move the tool through the operating cycle, and a guard supported by the machine-and movable to shield an area adjacent the working position, a control mechanism comprising a lever arm to move the guard to shield the area, a fluid controlled unit operable to actuate the clutch to render vthe power means effective, a, fluid line, a normally closed valve in the fluid line with the unit to control the ow of a fluid under pressure to the unit for actuating the unit when the valve is opened, means to actuate the lever arm, and a mechanism movable by the lever arm to open the valve, whereby the unit will render the power means elfective as the guardreaches approximately the area to be shielded.

2. A control mechanism for a machine having a material working tool mounted for movement through an operating cycle into and out of a working position, clutch controlled power means to move the tool thro-ugh the operating cycle, and a guard supported by the machine and movable to shield an area adjacent the working position, a control mechanism comprising a lever arm to move the guard to shield the area, a fluid controlled unit operable to actuate the clutch to render the power means eiective, a fluid line, a normally closed valve in the iluid line with the unit to control the flow of a fluid under pressure to the unit for actuating the unit when the valve is opened, means to actuate the lever arm, an actuable element positioned to operate the valve, and a member carried by the element and positioned to be engaged by the lever arm, when the latter has moved the guard to approximately the shielding location, to actuate the element.

3.' A control mechanism for a machine having a material working tool mounted for movement through an operating cycle into and out of a working position, clutch controlled power means to move the tool through the operating cycle, and a guard supported by the machine and movable to shield an area adjacent the working position, a control mechanism comprising a lever arm to move the guard to shield the area, a fluid controlled unit operable to actuate the clutch to render the power means effective, a fluid line, a normally closed valve in the iluid line with the unit to control the flow of a iluid under pressure to the unit for actuating the unit when the valve, is opened, means to actuate the lever arm, an actuable element positioned to operate the valve, and variable means carried by the element and positioned to be engaged by the lever arm, when the latter has moved the guard to a selected one of various positions adjacent the shielding position, to actuate the element.

4. A control mechanism for a machine having a material working tool mounted for movement through an operating cycle into and out of a working position, clutch controlled power means to move the tool through the operating cycle, and a guard supported by the machine and movable to shield an area adjacent the working position, a control mechanism comprising a lever arm to move the guard to shield the area, a fluid controlled unit operable to actuate the clutch to render the power means eifective, a iluid line, a normally closed valve in the fluid line with the unit to control the flow of a iluid under pressure to the unit for actuating the unit when the valve is opened, a fluid controlled unit to actuate thev lever arm, a variable speed control in a iluid line aaszaaeiv with the last mentioned unit to vary the speed of movement of the guard into its shielding location, and a mechanism movable by the lever arm to open the valve, whereby the first mentioned unit will render the power means effective as the .through an operating cycle into and out of a working position, clutch controlled power means to move the tool through the operating cycle,-

and a guard supported by the machine and movable to shield an area adjacent the working position, a control mechanism comprising a lever arm` to move the guard to shield the area, a fluid controlled unit operable to actuate the clutch to render the power means effective, a fluidv line, a normally closed valve in the fluid line with lthe unitL to control the ow of a fluid under pressure to the unit for actuating the unit when the valve is opened, means to actuate the lever arm, a mechanism movable by the lever arm to open the valve, whereby the unit will render the power means effective as the guard reaches approximately the area to be shielded, and a pressure control valve disposed in the fluid line to vary the pressure of the fluid to the unit.

6. A control mechanism for a machine having a material working tool mounted for movement through an operating cycle into and out of a working position, clutch controlled power means to move the tool through the operating cycle, a guard mounted to be rocked about a pivot into and out of a location to shield an area adjacent the working position, and operable mechanism to rock the guard, the control mechanism comprising a lever arm actuable to operate the said guard rocking mechanism, a iluid controlled unit operable to actuate the clutch to render the powerl means effective, a fluid line, a normally closed valve in the fluid line with the unit to control the flow of a fluid under pressure to the unit for actuating the unit when the valve is opened, means to actuate the lever arm, and a mechanism movable by the lever arm to open the valve, whereby the unit will render the power means eective as the guard reaches approximately the area to be shielded.

7. A control mechanism for a machine having a material working tool mounted for movement through an operating cycle into and out of a working position, clutch controlled power means to move the tool through the Operating cycle, a guard mounted to be rocked about a pivot into and out of a location to shield an area adjacent the working position, operable mechanism to rock the guard, a support, for the guard and its operable mechanism, whereby the guard and its operable mechanism may be supported in an operative position in front of the machine or Ibe moved to an inoperative position to one side thereof, the control mechanism comprising a lever arm formed for connection with the guard rocking mechanism when the latter is in its operative position to operate the said guard rocking mechanism, a fluid controlled unit operable to actuate the clutch to render the power means effective, a Huid line, a normally closed valve in the fluid line with the unit to control the flow of a fluid under pressure to the unit for actuating the unit when the valve is opened, means to actuate the lever arm, and a mechanismmovable by the lever arm to open the valve, whereby the unit will render the power means eiective arzaeei as. the guard reaches 'approximately the area to be shielded.

8.; A` control mechanism for a, machine having a material working tool mounted forfmovement through anv operating` cycle into and out of? a Working position4-` clutch controlled povver means to move the tool through the operating cycle,v a guard mounted to be rocked about a pivot, into and out of a location to shield an area adjacent.

anism, a fluid controlledunit operable to actnate` 20 17,166,981

the clutch to render the power means effective, a uixi line, a normally closed valve in the fluid line 8w wrthl the unit to control; the'ow of? a fluid: under pressure tol the unit for` actuating they unit when the valve isi opened, means; to actuate the leverV arm, and amechanism movable by the; lever arm to open the valve, whereby the unit will render the power means eiective when the guard is'. in its inoperative position and will render the power means ei'ective` only when the guard nears the shielding locationw-hen the. guard is in its operative position.

WALDEMAR C. EWALDSON.

REFERENCES CITED The following references are of recorcl` in the le oi this patent:

UNITED STATES PA'rEIsI'Is Number Name Date' 2,382,494 Magin Aug. 14, 1945 Graham Jan. 4, 1916 2,324,660 Yanchenko July 20, 1943- 

